The present invention relates to apparatus for mounting on a drag racing car to effect shifting of the automatic transmission precisely at a desired engine RPM, as well as to insure that the engine does not exceed certain maximum RPM levels. More specifically, the invention concerns electrical apparatus such as switches, relays, potentiometers and solenoids which operate in conjunction with a tachometer to provide automatic shifting at a selectively adjustable, predetermined RPM level, and limiting of the maximum RPM level.
According to established rules, the sport of drag racing involves accelerating a car from a standing start to a finish line, usually over a distance of 1/8 or 1/4 mile, in the shortest possible time. In order to achieve the optimum, shortest time for a given car, the driver must leave the starting line with the engine operating at an optimum RPM level, and must shift successively from lower to higher gears each time the engine reaches further optimum RPM levels. At the same time, the driver must ensure that the engine does not exceed certain maximum RPM levels in order to avoid possible damage to or destruction of the engine or other parts of the car. To this end, drag racing cars are provided with tachometers in order that the driver may be continually aware of the engine RPM level. However, constant observation of the tachometer diverts the driver's attention from the other aspects of vehicle operation.
Means have been provided to limit the maximum RPM of the engine while stationary at the starting line by applying a proportional ground to the ignition coil when the RPM level reaches a predetermined maximum. However, such devices are normally incorporated in an electronic device which determines the maximum RPM level, and which must therefore be replaced by another such device in order to change the level since this is a feature built into the device. Hence, there exists a need for means which permit selective adjustment of maximum RPM levels both at the starting line, as well as during a race, as well as means for automatically shifting to successively higher gears each time the engine reaches a selectively adjustable, predetermined RPM level.
In a general sense, the principal object of the present invention is to provide means for improving and optimizing performance of a drag racing car.
A more specific object is to provide means for automatically moving the shift lever of an automatic transmission to shift to successively higher gears each time the engine reaches a predetermined RPM level, including means for selective adjustment of such level.
A further object is to provide means for selective adjustment of the maximum RPM level of a drag racing vehicle engine both while racing the engine with the transmission engaged and the vehicle held stationary by the brakes at the starting line, and while the vehicle is in motion during a race.
Another object is to provide means for adjustment of RPM levels by bringing the engine to only one-half the actual operating level during the adjustment operation, thereby saving wear and tear on the engine.
A still further object is to provide means for limiting the maximum RPM level of a drag racing engine to a first value at the starting line and a second, higher value during a race, wherein normal operation of the vehicle causes a change from the first to the second maximum level.
Other objects will in part be obvious and will in part appear hereinafter.